Trussed structure



Dec. 27, 1927.

1,654,152 H. G. TREGILLUS TRUS SED S TRUCTURE Original Filed June 23., 1920 f Ewan/Z07":

Hamid, 6T TraqzlZu/s,

that

Patented Dec. B7, 1927.

UlTED STATES nAnoLn e. TREGILLUS, or rem: RIDGE, rumors.

'IRUSSED STRUCTURE.

firiginal application filed. June 23, 1920, Serial No. 391,035. Divided and. this application filed January 8,

My invention refers to trussed structures of the class disclosed in my Patent No. 1,330,771, of February 10th, 1920, the object of the invention being to provide modified truss formation which Will better adapt the trussed structures to varying conditions encountered in actual practice, while at the same time increasing the etiiciency and pen mitting the structures to be built with greater economy.

This application is a division of my copending application, Serial N0. 391,035, filed June 28, 199.0, for improrenilent in trussed structures.

In the form shown in the patent referred to, the anchoring or tension members entcnd from the ends of the arch member to intermediate points thereof, that is, the ends of the arch form the anchorage points for the anchoring members. Under certain con ditions it may be desirable to change the location of the anchoring point or points. For example, Where the span is so long that the stock material for the anchoring members would not be long enough, it would be desirable to shift the anchorage points to permit the use of shorter anchoring menu hers, Under other conditions, it might also be desimble to shift the anchoring points away from the ends of the arch or truss. In the structure of my patent above referred to, We have an inverted Bellman truss structure associated with an arch member and with this arrangement the anchorage points are at the arch ends. By changing the form of the inverted truss structure, the unchorage point or points, i. e., the point or points of utiplication of the arch retaining tension members, can be shifted from the arch ends to some intermediate point or points on the truss structure and such shifting of the anchorage points Will permit the use of shorter tension members for connecting the point or poi. of anchorage with the arch.

The structure of which the shifted anchor age points form a part, I call. the inverted truss structure or formation, and the combination of this inverted truss formation With the arch member and the tension memhers I call the trussed structure.

In operation, then, the inverted truss f0rmotion is anchored. to the arch ends, and intermediate points on the arch are anchored to a predetermined anchorage point, or pre determined anchorage points on the chord Serial. No. 1,306.

member of the inverted truss formation by means of tension members.

On the accompanying drawing, my invention, is lllCOl'fiOltLtGCl and illustrated in a trussed structure showing modified inverted truss formation. In this drawing,

Figure 1 is a side elevational View of one form of structure.

Figure 2 is a sectional. View on line 22, Figure 1.

Referring to Figure 1 the trusscd structure shown comprises the arch member 10, tension members 11 and an inverted truss formation to which the arch member is anchored by the tension members. The in Verted truss formation or structure shown comprises the chord member 12, the inverted trusstension members 13 and 14: and the strut member in the form of a kingpost 15 connecting between the juncture of the truss tension members and the chord member 12. .As shown in Figure 2 the arch member may be composed of twe angle bars at, and the chord member 12 may be composed of two angle bars Z), While the strut member may be composed of two angle pieces a secured at their upper cues to plate (Z and at their lower ends to plates 0, the plate d being secured to the arch member bars a and the plates 6 being riveted to the chord member bars 5. The chord and arch members are connected together at their ends by Web plates f and g to which the truss tension members 13 and 14- are also secured, the inner ends of these members being secured to the plate (Z. The truss structure is thus co11- nected directly to the arch member at the ends and center thereof. The pirates 6 form an anchorage for the tension members 11 which radiate therefrom and connect with the arch member at intermediate points thereof. The principle of operation of this trussed structure the same as that disclosed in. my patent referred to, the tension members together With the truss formation n'eventing bulging of the arch member during application of irregular load thereto, and consequently preventing flattening of the arch member at other points.

Primarily the anchorage points are at the ends of the arch which are held properly spaced by the chord member 12 which be comes the tension chord of the trussed structure when under load. By means of the truss formation or structure extending between. the

arch ends, the anchorage points can be shifted to any desired location on the truss structure. In Figure 1, the shift has been made to the center of the chord member 12, and 0wing to the rigid truss formation the point of anchorage represented by the plates 6 is positive. By thus shifting the anchorage much shorter tension. members 11 can be used, and there are many advantages in the use of such shorter tension members.

In the structure shown on the drawings of my patent, the arch retaining members form necessary parts of the inverted Bollman truss structure, while in the arrangement of this application the inverted truss a structure complete in itself, arch retaining members radiating to the arch member from selected points of anchorage on the truss. In the structure shown on the drawings of the patent, the inverted Bollman truss formation comprises only tension members, While in the arrangement disclosed in this application the truss formation comprises both tension and compression members.

In order that the term inverted as applied to the truss formation shall be clearly understood, it is pointed out that any truss for supporting loads, that is, to resist downward forces, is not inverted and has the main tension member at the bottom. The truss formation of my invention is for resisting upward forces, and has its main tension member at the top. It is therefore an inverted truss.

Having described my invention, I claim as follows:

1. A roof truss comprising an arch, a main chord for the same, a pair of secondary chords respectively spanning half of the arch, a strut disposed medially of the truss and connecting the arch with the main chord, and bracing means associated with each half of the truss for resisting an increased couvexing ot' oue-half of the arch by an excessive loading of the other ha] i thereof.

The combination of an arch, a triangle of tension members haviu; two of its corners directly attached to the arch ends and the remaining corner directly attached to an intermediate point on the arch, a strut joining said intermediate point on the arch and the opposite side of said triangle, and tension members joining the lower end of said strut and said arch at. various points thereon.

3. The combination of an arch, a chord for the arch, two sub-chords for consecutive portions of the arch, a post joining the two subchords, at their juncture, to the chord, and tension members joining various portions of the arch to the post at its juncture with the chord.

In witness whereof, I hereunto subscribe my name this 7th day of January, A. 1)., 1925.

HAROLD G. 'lR-EGILLUS. 

